Aurizon Minerals has reported a 44% increase in mineral reserves at its Casa Berardi mine in northwestern Quebec.
That brings the gold reserves to 1.457 million ounces, with 370,000 ounces available for open pit mining in the principal zones, which are open laterally.
The Casa Berardi mine has produced over 1.3 million recovered gold ounces since commencing production in 1986, including 636,400 recovered ounces since Aurizon recommenced production in November 2006.
A prefeasibility study on the principal open pit, commmissioned by BBA Inc., explains the reasons for the gains in proven and probable reserves:
At the West Mine, the 2010 mine production in Zones 113, Lower Inter, North West and 115 have been more than replaced by gains in mineral reserves primarily from the Principal Zone open pit and Zone 123S. Additional reserve increases were provided from Zones 118 and 109.
As a result of the addition of the lower grade ore from the Principal Zone open pit, tonnage has increased by 77%, grade has decreased by 19% and ounces of gold have been increased by 44% compared to 2009.
Mineral reserves are estimated using an average long-term gold price of US$950 per ounce and a US$/C$ exchange rate of 1:1, compared to US$825 per ounce in 2009 and a US$/C$ exchange of 1:1.09. A minimum cut off grade of 4.1 grams of gold per tonne was used for the underground zones, based on long term operating costs and gold prices. A minimum cut off grade of 1.2 grams and 0.5 grams of gold per tonne was used respectively for the East Mine and Principal Zone open pits. In 2009, the minimum cut off grade was 3.9 grams of gold per tonne for the underground zones.
As the mining industry is currently experiencing gold prices that are higher than US$950 per ounce, the operations periodically mine ore that is not included in mineral reserves as the grades are lower than the long term minimum cut-off grades.
Aurizon envisions the principal open pit as a smaller-scale operation with a mine life of three years. An average 500,000 to 550,000 tons of ore will be moved every six months.
President and CEO David Hall noted that Aurizon has renewed or increased its mineral reserves for four straight years. The company's $13.4 million exploration program is planning for 115,000 metres of diamond drilling, en route to completing a scoping study for open-pit mining Zone 160. The recently extended drift on the 550 level will be used as a drilling platform to test for continuity between the principal zone and zones 118 and 123. The West Mine shaft will also be deepened from the 760 to the 1080 metre level as another platform for exploratory drilling.
To learn more click here